Imperial College of Science and Technology, Department of Physics, London, United Kingdom
Muons, Inc, Batavia, USA
JLAB, Newport News, Virginia, USA
JLAB, Newport News, Virginia, USA
Muons, Inc, Batavia, USA
Recirculating Linear Accelerators (RLA) are an efficient way of accelerating short-lived muons to the multi-GeV energies required for Neutrino Factories and TeV energies required for Muon Colliders. In this paper we present a design of a two-pass RLA return arc based on linear combined function magnets, in which both charge muons with momenta different by a factor of two are transported through the same string of magnets. The arc is composed of 60°-bending symmetric super cells allowing for a simple arc geometry closing. By adjusting the dipole and quadrupole components of the combined-function magnets, each super cell is designed to be achromatic and to have zero initial and final periodic orbit offsets for both muon momenta. Such a design provides a greater compactness than, for instance, an FFAG lattice with its regular alternating bends and is expected to possess a large dynamic aperture characteristic of linear-field lattices.
BNL, Upton, Long Island, New York, USA
JLAB, Newport News, Virginia, USA
We present a design of the proton therapy accelerator from 31 MeV to 250 MeV by using racetrack lattice made of Non-Scaling Fixed Field Alternating Gradient (NS-FFAG) arcs and two parallel straight sections. The magnets in the arcs are separated function Halbach type magnets. The dipole bending field is 2.3 T, while the Neodymium Iron Boron magnetic residual induction is Br=1.3 T. The radial orbit offsets in the NS-FFAG arcs, for the kinetic energy range between 31 MeV < Ek < 250 MeV or momentum offset range -50% < δp/p < 50%, are -11.6 mm < x max < 16.8 mm, correspondingly. The straight sections used for the cavities and single turn injection/extraction kickers and septa are with zero orbit offsets. The permanent magnets accelerator should reduce overall and operating cost. It could fit into 8 x 12 m space.
JLAB, Newport News, Virginia, USA
ODU, Norfolk, Virginia, USA
Medium Energy Electron Ion Collider (MEIC) at JLab has been envisioned as future high energy particle accelerator beyond 12 GeV upgrade of CEBAF. Crab crossing of colliding electron and ion beams is essential for accommodating high bunch repetition frequency in the conceptual design of MEIC. The scheme eliminates parasitic beam-beam interactions and avoids luminosity reduction by restoring head-on collisions at interaction points. This requires the separation of two beams quickly to avoid parasitic collisions and the minimization of synchrotron-betatron resonance near IP which can be fulfilled by employing the crab crossing concept first proposed by R. Palmer. Let us call this original scheme as transverse crabbing for the sake of comparison with dispersive crabbing which employs the existing accelerating/bunching RF cavities and dispersion function in the section where the cavity is installed as originally proposed by G. Jackson. In this paper, we report the beam transport and optics for both transverse and dispersive crabbing schemes followed by basic beam dynamics. Moreover, alignment and stability calculations together with synchro-betatron beam dynamics will be discussed.
BNL, Upton, Long Island, New York, USA
JLAB, Newport News, Virginia, USA
Numbers of proton/carbon cancer therapy facilities in recent years is rising fast due to a clear advantage with respect to the other radiation therapy treatments. Cost of the ion cancer therapy is dominated by the delivery systems. An update on a design of the carbon and proton isocentric gantries is presented, using the non-scaling alternating gradient fixed field magnets (NS-FFAG). Size and weight of these magnets much smaller than any other magnets used today in cancer therapy treatment. The weight of the transport elements of the carbon isocentric gantry is estimated to be 1.5 tons to be compared to the 130 tons weight of the top-notch Heidelberg facility gantry. For the transport elements of the proton, the permanent magnet isocentric gantry is 500 kg.
JLAB, Newport News, Virginia, USA
Muons, Inc, Batavia, USA
Northern Illinois University, DeKalb, Illinois, USA
Parametric-resonance Ionization Cooling (PIC) is proposed as the final 6D cooling stage of a high-luminosity muon collider. For the implementation of PIC, we developed an epicyclic twin-helix channel with correlated optics. Wedge-shaped absorbers immediately followed by short rf cavities are placed into the twin-helix channel. Parametric resonances are induced in both planes using helical quadrupole harmonics. We demonstrate resonant dynamics and cooling with stochastic effects off using GEANT4/ G4beamline. We illustrate compensation of spherical aberrations and benchmark COSY Infinity, a powerful tool for aberration analysis and compensation.
JLAB, Newport News, Virginia, USA
An achromatic Interaction Region (IR) design concept is presented with an emphasis on its application at an electron-ion collider. A specially-designed symmetric Chromaticity Compensation Block (CCB) induces an angle spread in the passing beam such that it cancels the chromatic kick of the final focusing quadrupoles. Two such CCB’s placed symmetrically around an interaction point (IP) allow simultaneous compensation of the 1st-order chromaticities and chromatic beam smear at the IP without inducing significant 2nd-order aberrations. Special attention is paid to the difference in the electron and ion IR design requirements. We discuss geometric matching of the electron and ion IR footprints. We investigate limitations on the momentum acceptance in this IR design.